NAVAIR Stretching Additive Manufacturing’s Limits
By NICK ADDE, Seapower Special Correspondent
NATIONAL HARBOR, Md. — At past Sea-Air-Space expositions, Liz McMichael — the team lead of additive manufacturing and digital thread at Naval Air Systems Command (NAVAIR) — promised that critical parts made through additive manufacturing would fly. Last year, she went so far as to champion the fact that a part or two actually flew.
This year is different, McMichael told an audience during an April 9 presentation at the Sea-Air-Space exposition.
“I’m very excited to say we’ve had a lot more than one,” McMichael said. “The focus now is on other readiness drivers that we think we can do much faster and easier, to get the technology into the hands of users and let them solve their problems.”
The solution sounds like it should be easier than it actually is, McMichael said. Using a 3-D printer to manufacture a few parts is simple. Making them for thousands and eventually millions, and ensuring that they are safe, airworthy and robust enough for use in the fleet, is considerably more complicated.
Consider the fact that many potentially printable parts would be made of metal, and the matrix grows more complicated, McMichael said.
Greg Welsh, NAVAIR’s expert in the application of additive manufacturing of metal components, descried the command’s road map for it. He cited the July 2016 flight of a V-22 Osprey that had such a part.
“As we move on from the V-22 demo, we’re scaling up and out – beyond just titanium – to some steel and aluminum parts,” said Welsh, a materials engineer.
Before additive manufacturing can be used routinely to produce such parts, problems inherent with the differences among metallic powders available from different vendors must be taken into consideration. So too should be the distortion inherent to the process, which could affect portability and dimensional tolerances. NAVAIR is exploring “multiple techniques” to resolve such issues, Welsh said.
“What this really talks to is research,” McMichael said. “How to make it all easily usable — a batch process.”
She described issue with the oxygen-generation system on T-45 Goshawk trainers, which led to their grounding from April to July of last year. While engineers went to work on a permanent solution, they asked McMichael and her peers to come up with a temporary fix — a mask that could let students fly while breathing cabin air, and be able to close the air off if they needed to eject.
McMichael said they quickly built the part using additive manufacturing, but NAVAIR needed more than her office’s eight printers could produce – 300 in all – by last June 5. She sought and got help from Naval Sea Systems Command (NAVSEA) and other offices, eventually getting printers at six different sites working on the part.
“We met the timeline, about 15 days start to finish,” McMichael said.
“I think we can go faster. What we learned is it wasn’t the technology holding us up. It was the business process,” she said.
Fixing it would take the right contracts, digital infrastructure and networks in place that would allow for proper coordination with industry, she said.
“If we can do that, I think 15 days is too long,” McMichael said.